Certain methods of this type for operating a parallel hybrid drive of a vehicle are conventional, the vehicle being a motor vehicle in particular. The hybrid drive of a vehicle has a drive train which includes an internal combustion engine and at least one electric machine. In the drive train of a parallel hybrid drive, the internal combustion engine may be coupled to the electric machine via a disconnecting clutch influenceable by a vehicle controller. In addition to the hybrid, boost, and recovery operating modes, a purely electric operation is also possible. A start of the internal combustion engine may be necessary even during the electric driving operation. This is the case, for example, when the driver is requesting more power than the electric machine is capable of delivering, or when the charge state of an electric accumulator supplying the electric machine has dropped substantially. A start of the internal combustion engine from electric operation takes place by engaging the disconnecting clutch while driving, and thus with the electric machine rotating, and with the internal combustion engine initially at rest. When the disconnecting clutch is engaged, the internal combustion engine is entrained, while the angular velocity of the electric machine initially drops. When the internal combustion engine gains speed as a result of the first firings, an overshoot of the rotational speed of the internal combustion engine may occur, which results in a temporary increase in the angular velocity of the electric machine. The drop and temporary increase in the angular velocity affect the drive train and impair the driving comfort.